This invention relates to devices used to manufacture or assemble firearm ammunition using either new or used metallic cartridge cases. Specifically, this invention combines the necessary means to trim cartridge cases to a predetermined length while removing burrs and chambering both the inside and outside of the case mouth, remove cartridge case material used to crimp primers into the cartridge case by swaging, cutting the cartridge case primer pocket to a predetermined depth, chambering both the inside and outside surface of the cartridge case flash hole, and trimming the wall thickness of the cartridge case neck to a uniform dimension, all with the same device and by a manner that increases convenience and accuracy over any other means currently available.
Description of Prior Art
Numerous machines have been invented to perform the necessary steps to recondition and reuse fired cartridge cases. During the physical act of firing a modern firearm using metallic cartridge cases, the case expands slightly due to the high pressure contained inside the cartridge case. The case is contained on all but one surface by the firearm""s chamber so that the projectile is forced to leave the cartridge case and travel through the barrel to the muzzle and towards its intended target by the intense pressure released or generated by the propellant. Once the firing process has concluded, the now empty cartridge case may be removed from the firearm and either discarded or reused.
It is standard accepted practice to resize or swage the cartridge case into a metallic die to reform the case to its proper dimensions, which were distorted by the high pressures generated during the previous firing. When the cartridge case is resized, the diameters of the case are reduced slightly so the case may then be reinserted into a firearm""s chamber without interference. Without resizing, the cartridge case may not enter a chamber and function as intended. While the resizing process reduces the diameters of the case along its main axis, the material displaced lengths the cartridge case along the major axis of the case. Typical values of overall length increase range from 0.002xe2x80x3 to 0.015xe2x80x3 per firing and resizing sequence. When using the existing known art to resize a cartridge case, the additional length appears at the mouth of cartridge case. It is then necessary to remove the excess material before reusing the case.
To remove this excess material from the cartridge case mouth, some type of mechanical process is used to cut the material off of the cartridge case while leaving the head of the case undisturbed. Typical devices currently used include the use of a rotating cutter(s) acting on a fixed case held by the case head, rotating cutter(s) acting on a fixed case held by some type of gage or die, rotating cutter(s) acting on a case inserted into some type of fixed gage or die, or files used to remove the case material exposed above a gage surface. These devices all leave the cartridge case mouth in full contact with the cutting device until manually removed. Most of these current devices also leave burrs along the freshly cut surface of the case mouth, which must be removed to safely reuse the cartridge case. If the burrs are not removed from both the inside surface and outside surface of the case neck before a projectile is inserted in the cartridge case, then into a firearm""s chamber, excessive force may be applied to the projectile by the chamber walls acting like a clamp or collet holding device restricting its ability to leave the cartridge case and cause increased pressures inside the firearm chamber.
While many devices exist to trim the excess material from a resized metallic cartridge case, none are known to index the cartridge case to the cutting surfaces and remove the case from the cutting surface automatically or prevent the case from contacting the cutting surface without some action, namely physically moving the cutter and case away from each other.
Accordingly it is an object of this invention to trim the mouth of resized cartridge cases to the desired overall length by indexing the case off some known repeatable point of the case other than the case head, chamber the case mouth edges on both the inside and outside and outside surfaces, and automatically withdraw the case from the cutting blade when additional manual force is not applied. The cutting of material from the case neck stops when the cartridge case has engaged the case holder assembly and the moving portion of the case holder assembly reaches a mechanical stop. Withdrawing the case from the cutting surface occurs when the manual pressure applied to the case during the trimming process is removed. A spring device lifts the cartridge case away from the cutting surface until the user applies some pressure to the case to force the case towards the cutting surface, and away from the cutting surface once the user added pressure is removed.
To reuse cartridge cases that have had the primer swaged or staked in place, it is necessary to first remove the used primer and recondition the primer pocket to remove the material displaced by the swaging process. Without removing this material, a new cartridge primer cannot be inserted properly because the exposed edge of the primer pocket is dimensionally smaller than the remaining depth of the pocket and the outside diameter of a new primer. Existing devices used for this process are typically one of two types, those cutting material from the case, and those that swage the material back away from the cartridge case primer pocket using a mechanical force. With either device it is desirable, for more accurate ammunition, to make the finished primer pocket as uniform in dimension as possible and with a flat bottom in the primer pocket perpendicular to the cartridge case main axis. By using a mechanical cutting device to remove the displaced material away from the primer pocket and cut the bottom of the primer pocket flat, the overall dimensional accuracy of the finished primer pocket is higher than with a swaging type device. The overall dimensional uniformity from case to case in a given lot of cartridges will greatly influence the accuracy potential of the cartridges when fired. Ammunition prepared with cartridge cases using uniformed primer pockets will be generally yield a smaller dispersion around an aiming point, a very desirable feature for users trying to achieve the utmost in accuracy.
Other devices exist for removing the excess material and cutting the bottom surface of the primer pocket, but typically are two step devices. One step is to remove the excess material, and another to cut the flat surface of the pocket. One other device is known to exist the combines these two steps into one process. While there are several known tools to remove the excess material and uniform the bottom of the primer pocket, none are known to be combined with a cartridge case trimmer that automatically removes the case from the cutting surface.
To facilitate more uniform ignition of propellant inside a cartridge case typically yields a more accurate cartridge. Accordingly, it is common practice to remove any burrs present around the opening inside a cartridge case between the primer pocket and the inside of the cartridge. This passage is typically known as the flash hole. If burrs are present on either side of the flash hole, the flame released from the primer upon detonation may not enter the cartridge case main body to ignite the propellant in an even manner. Propellant ignited from an even axially centered flash produces more uniform ignition and combustion than that ignited by a flash entering the cartridge case main body in some random orientation. As is seen with uniforming primer pockets, ammunition prepared with cartridge cases having the flash hole surfaces deburred will typically yield a smaller dispersion than those without the benefit of the deburring process. Typically known devices for deburring the flash hole of cartridge cases use a small metal cutting bit to chamber the edge of the flash hole from both the inside and outside of the case. This will remove any burrs remaining from the punching process typically used in the manufacture of cartridge cases.
There are several known varieties of tools used to deburr the flash hole of a cartridge case, but none are known to be combined with the previously mentioned devices that can automatically remove the cartridge case from the cutting action.
Metallic cartridge cases are typically manufactured by a deep drawing process to extrude the basic shape and form of the cartridge case from a strip of brass alloy material. During the initial forming and subsequent resizing for reuse, the wall of the cartridge case neck can become uneven or non-uniform in thickness. Cartridge cases with a case neck of uneven thickness can affect the case""s ability to release the projectile during the firing process. By removing the additional material around the case neck and making the case neck wall thickness more uniform, the initial movement of the projectile out of the cartridge case is more properly aligned with the bore of the barrel. By aligning the projectile closer to the true axis of the barrel, the projectile""s path down the barrel and to its intended target is straighter and more accurate. Existing devices to remove this excess material all use some type of cutting blade aligned perpendicular to the axis of the cartridge case and support the case neck by use of a mandrel inside the case neck. The purpose of the mandrel is to ensure the case neck wall thickness is uniform and aligned with the axis of the case. If the excess material in the cartridge case neck is removed without supporting the case neck very close to the cutting action, the case neck will deflect away from the pressure of the cutting tool and an uneven surface will result. Known devices exist that use an automated feature of the device to move the cutter across the surface of the case neck parallel to the axis of the cartridge case and others use hand pressure to move the cutting across the surface. This procedure can be accomplished by rotating the cartridge case around a fixed cutting blade and mandrel assembly or by the cutting blade and mandrel rotating around a fixed cartridge case held in place.
While there are several known varieties of devices to accomplish trueing, turning, or shaving the cartridge case neck, none are known to combine this with trimming the overall length of the case, removing the staked or swaged material from a primer pocket, uniforming the primer pocket size, shape, and depth, and deburring the flash hole of a cartridge case into one device or with the ability to withdraw the case from the cutting surfaces automatically.
Accordingly, it is an object of the present invention to trim the overall length of a cartridge case and remove burrs on both the inside surface and outside surface of the case mouth at the same time, remove excess material from the cartridge case primer pocket, uniform the cartridge case primer pocket size, shape, and depth, deburr the flash hole of a cartridge case, and true, turn or shave the cartridge case neck with one device by the using interchangeable accessories on a single device. Another object of the present invention is to withdraw the case from the cutting surfaces of each operation by using a case holding device that will move the case when the manual pressure used to hold the cartridge case in the cartridge case holder assembly is removed.
In one embodiment of the invention, a base is constructed to hold and position body housing bearings, a rotating shaft, cartridge case positioning device, a power source, and control device. This base will allow the orientation of the devices mounted to the base to changed easily from horizontal to vertical without any additional parts or necessary modifications. The bearings in the body housing support the rotating shaft aligned axially with a removable cartridge case position device. A power source, positioned also on the base, drives the rotating shaft. The rotating shaft has provisions to mount interchangeable sections on the end opposite the driving device. Each different interchangeable section may be attached to the end of the rotating shaft and are designed to perform a one or more of the functions described above. The removable cartridge case holder has an internal profile closely matching the specific caliber of cartridge desired and the portion of the cartridge case to be inserted, and is constructed in such a manner as to lift the cartridge case away from any device attached to the rotating shaft when not acted upon by some force. Some interchangeable cartridge case holders are intended to position a case with the neck of the case presented to the rotating shaft, others are intended to position a case with the head presented to the rotating shaft.
When trimming a cartridge case using the invention, a case is inserted into the case holder by hand while the power source drives the rotating shaft. The rotating shaft is equipped with the case trimming interchangeable section holding a cutting blade that has surfaces positioned to remove material from the overall length of the case, as well as remove burrs or chamber both the inside and outside surfaces of the case mouth. The case holder is designed to allow the cartridge case to be inserted into the inner portion until some surface of the case contacts a mating surface inside the inner portion of the case holder and the case neck projects beyond the surface of the case holder. Once the case is in contact with the inner portion of the case holder, the inner portion and case move together towards the cutting blade and against a spring contained in the space between the inner and outer portions of the case holder assembly. A final mechanical stop is formed between the inner and outer portions of the case holder assembly. Once these two surfaces meet, the cartridge case cannot move toward the cutting blade any further. As the case mouth contacts the rotating cutting blade, excess material is removed and the edges of the case mouth are chambered. Once the rotating blade has removed the material desired, the cases is then released and the captive spring will life the case and inner portion of the case holder away from the rotating cutting blade. If the unit is positioned with the rotating shaft in a vertical orientation, any debris created by the removal of the excess material will fall away from the case holder and case, falling into the chamber created by the body and cover around the cutting blade. If the device is positioned with the rotating shaft in a horizontal position, any debris from the cutting action can fall into the inner portion of the case holder assembly when the case is removed from the device. If the debris is not removed before the next case is inserted into the case holder assembly, it is possible to falsely index the case to the cutting surfaces by resting on the debris and not the intended inner surface of the case holder.
When using the invention to remove the material swaged into the primer pocket, a case is inserted into the case holder by hand while the power source drives the rotating shaft. The rotating shaft is equipped with the primer pocket deswaging interchangeable section holding a cutting blade that has surfaces positioned to remove material from the edge of the cartridge primer pocket. The case holder is designed to allow the cartridge case to be inserted into the inner portion until some surface of the case contacts a mating surface inside the inner portion of the case holder and positioning the head of the case towards the cutting blade. Once the case is in contact with the inner portion of the case holder, the inner portion and case move together towards the cutting blade and against a spring contained in the space between the inner and outer portions of the case holder assembly. As the primer pocket edges of the case contact the rotating cutting blade, excess material is removed and the edges of the primer pocket are chamfered. Once the rotating blade has removed the material desired, the case is the released and the captive spring will lift the case and inner portion of the case holder away from the rotating cutting blade. If the unit is positioned with the rotating shaft in a vertical orientation, any debris created by the removal of the excess material will fall away from the case holder and case, falling into the chamber created by the body and cover around the cutting blade.
When using the invention to cut the primer pockets of several cases to a uniform set of dimensions, a case is inserted into the case holder by hand while the power source drives the rotating shaft. The rotating shaft is equipped with the primer pocket uniforming interchangeable section holding a cutting blade that has surfaces positioned to remove material from the sides and bottom of the cartridge case primer pocket. The case holder is designed to allow the cartridge case to be inserted into the inner portion until some surface of the case contacts a mating surface inside the inner portion of the case holder and positioning the head of the case towards the cutting blade. Once the case is in contact with the inner portion of the case holder, the inner portion and case move together towards the cutting blade and against a spring contained in the space between the inner and outer portions of the case holder assembly. As the primer pocket surfaces contact the rotating cutting blade, excess material is removed and the primer pocket is uniformed. Once the rotating blade has removed the material desired, the case is the released and the captive spring will life the case and inner portion of the case holder away from the rotating cutting blade. If the unit is positioned with the rotating shaft in a vertical orientation, any debris created by the removal of the excess material will fall away from the case holder and case, falling into the chamber created by the body and cover around the cutting blade.
When using the invention to remove any burrs and chamber the edges of a cartridge case flash hole, a case is inserted into the cases holder by hand while the power source drives the rotating shaft. The rotating shaft is equipped with the flash hole deburring interchangeable section holding a cutting blade that has surfaces positioned to remove material from the edge of the cartridge case flash hole. The case holder is designed to allow the cartridge case to be inserted into the inner portion until some surface of the case contacts a mating surface inside the inner portion of the case holder and the case neck projecting beyond the surface of the case holder. Once the case is in contact with the inner portion of the case holder, the inner portion and case move together towards the cutting blade and against a spring contained in the space between the inner and outer portions of the case holder assembly. As the edges of the flash hole contact the rotating cutting blade, excess material is removed and the edges of the edges of the flash hole are chamfered. Once the rotating blade has removed the material desired, the case is the released and the captive spring will lift the case and inner portion of the case holder away from the rotating cutting blade. If the unit is positioned with the rotating shaft in a vertical orientation, any debris created by the removal of the excess material will fall away from the case holder and case, falling into the chamber created by the body and cover around the cutting blade.
When using the invention to true, turn or shave excess material from a cartridge case neck wall, a case is inserted into the case holder by hand while the power source drives the rotating shaft. The rotating shaft is equipped with the case neck turner interchangeable section holding a cutting blade that has surfaces positioned to remove material from the outer surface of the cartridge case neck while supporting the case neck with a mandrel inside the case neck. The case holder is designed to allow the cartridge case to be inserted into the inner portion until some surface of the case contacts a mating surface inside the inner portion of the case holder and the case neck projecting beyond the surface of the case holder. Once the case is in contact with the inner portion of the case holder, the inner portion and case move together towards the cutting blade and against a spring contained in the space between the inner and outer portions of the case holder assembly. As the outer surface of the case neck contact the rotating cutting blade, excess material is removed and the case neck wall thickness is turned to uniform thickness. Once the rotating blade has removed the material desired, the case is the released and the captive spring will lift the case and inner portion of the case holder away from the rotating cutting blade. If the unit is positioned with the rotating shaft in a vertical orientation, any debris created by the removal of the excess material will fall away from the case holder and case, falling into the chamber created by the body and cover around the cutting blade.
This invention has alternate embodiments with a rotating shaft configured to only trim cartridge cases or deswage primer pockets or uniform primer pockets or deburr primer pocket flash holes or neck turn cartridge case necks and not perform the other functions listed above by using a rotating shaft without the interchangeable sections, i.e. dedicated function devices rather than a multiple function device, but still automatically withdraw the case from the cutting surface when manual pressure is not applied. Another alternate embodiment of the invention uses a variable speed power source. This will allow the user to set the speed of the rotating shaft and attached cutting surfaces of the speed best suited for the operation performed.
These and other features of the present invention will be apparent to those of skill in the art from a review of the following detailed description along with the accompanying drawings.